CERN JUG Meet-up #3 - Take Control of Your Build: Spring Boot and Beyond with Mill

Tuesday 2 Dec 2025, 18:00 → 19:30 Europe/Zurich

503/1-001 - Council Chamber (CERN)

Welcome to the CERN Java User Group Meet-up #3: Take Control of Your Build: Spring Boot and Beyond with Mill

This event offers a unique opportunity to those passionate about Java and modern engineering practices to engage with the CERN developer community and beyond. Whether you are a CERN member or an external visitor, we invite you to join us for an evening of learning and networking.

• Registration: To subscribe to news about future events and meetups, please use the CERN JUG mailing list. Those of you coming from the outside of CERN will need to create a guest account as explained here.

• External visitors: If you are coming from outside CERN, we will arrange a badge for you upon registration. Badges are necessary for site access and will be printed for your convenience.

• Date & Time: 02 December 2025, 18:00–19:30

• Venue: Council Chamber, CERN

 

For any questions, please contact the organizing team at cern-jug-organizers@cern.ch.

 

 

18:00 → 19:00 Take Control of Your Build: Spring Boot and Beyond with Mill

Modern Java builds have become complex, opaque, and hard to reason about. Build tools often hide their logic behind bespoke Domain-Specific Languages (DSLs), made even harder to follow through layers of plugins. Mill takes a different approach: a fast, comprehensible, and fully programmable build tool based on Scala’s object-oriented and functional capabilities, where your build definition is idiomatic code you’re used to, not arcane configuration.

In this talk, we’ll explore how Mill’s task-graph model, composable modules, and source-level transparency give developers precise control and deep insight into their builds. We’ll look at practical examples relevant to Spring Boot projects, including dependency management and pre-processor/annotation-processor workflows. We’ll then push Mill to its limits by looking at the complexity of the Android build process, showing how Mill is able to support even the most complex build configurations.

Attendees will leave with a clear understanding of how Mill differs conceptually from Gradle and Maven, why its explicitness and readability matter for large organisations like CERN, and how to leverage Mill’s power to make Java, Spring Boot, Kotlin, and any other sophisticated build configurations more comprehensible and user-friendly.

Speaker: Mr Vasilis Nicolaou (Vaslabs LTD)